Control for electric heating devices



Nov. 14,

L. IRELAND CONTROL FOR ELECTRIC HEATING DEVICES Filed Feb. 21, 1930 1' nrenior. L dwrence Ire/and &

Patented Nov. 14, 19.33

I ED STATES PATENT oFFICE v CONTROL FOR ELECTRIC HEATING DEVICES jLawrence'I rel'and, Guelph, Ontario, Canada, as-

slgnor toThe TrEaton Company, Limited, To- A ronto, Canada Application February 21,1930. Serial No. 430,3 90

Claims. (01. 200+51) Theprincipal objects of this invention are to overcome the inconveniences and difficulties caused by the failureof automatic control the improved shunt.

Figure 2 is an elevational view of the shunt showing the contacts closed with the automatic switch removed.

Figure 3 is a perspective detail of the socket plate of the shunt showing the contact pins of the automatic control switch.

Figure 4 is a perspective detail of the spring contacts and supporting plate of the shunt.

The base plate 1 of the automatic control switch herein shown is removably mounted on the frame 2 of the heating device and it is provided with a contact pin 3 which is electrically connected to the automatically operated switch member 4.

, A plurality of contact pins 5 are preferably mounted in a row on the base plate 1 and electrically connected with the adjustable contacts 6 of the automatic control switch.

The pins 3 and 5 are formed with inwardprojecting portions 3' and 5' respectively which extend through holes 7 and 8 in an insulating plate 9 secured to the frame 2. r

A metal plate 10 issecured to the inner face of the plate 9 and is provided with holes 7 and 8' which are considerably larger than the holes '7 and 8 in the insulating plate and are concentric therewith. I

The pins 3 and 5 project through the holes 7, '7' and 8, 8' and extend beyond the inner face of the metal plate 10. i

A plate 11 of insulating material is spaced from the plate 9 and has secured on themes adjacent to the plate'9 a spring contact 12 which is engaged by the projecting portion 3' of the pin 3 and held thereby from contact with the metal plate 10.

A plurality of spring contacts 13 are secured on the plate 11 and are'engaged individually by the projecting portions 5 of the pins 5 and held thereby from contact with the metal plate 10.

The contacts 12 and 13 are adapted, on the withdrawal of the pins 3 and 5 from the holes in the plate 9,.to engage the metal plate 10 in electrical contact.

The electric heating elements, not shot are to connected with the contacts 13 by leads 14 and a lead 15 is connected to the contact 12. These leads connect through the manual controls of the heating device in any desired arrangement. The Wiring circuit is not shown asitis imma- -terial to the present invention.

Ordinarily when the portions 3' and 5' of the pins 3 and 5 respectively are in contact with the contacts 12 and 13 the circuits are controlled by the automatic operation of the member 4 in 00- operation with the contacts 6, but in the event of the automatic control device failing, for any reason, the base plate 1 may be disconnected from the frame and the whole automatic device removed withdrawing the pins 3 and 5 and thus releasing the spring contacts 12 and 13 allowing them to engage the plate 10 which thus forms a shunt between the leads 14 and 15 and the heating elements can then be controlled by the manual switches.

What I claim as my invention is:

1. In an electric heating device, the combination of a switch having switch elements adapted to open and close automatically, a plurality of contact pins electrically connected with the automatic switch elements, an insulating block through which said pins extend, an electrical conductor mounted on the rear of said insulating block and notched to clear said pins, an insulating plate spaced rearwardly of said perforated block, and a plurality of spring contacts mounted on said insulating plate and having their free ends disposed rearwardly of said electrical conductor and extending transversely across the path of said pins to be engaged and depressed rearwardly from said electrical conductor by contact with the I innerend extremities of the pins, said spring contacts being adapted on the withdrawal of saidv pinsto move forwardly. to engage said conductor. 2. In a shunt for electric control switches, the combination with a switch having switch elements opening and closing automatically, said switch elements having a plurality of contact pins electrically connected therewith, of an insulating block having a plurality of guide openings therein through which said pins extend, a metal plate secured to the inner side of said block and having openings larger than the aforesaid guide openings and concentric therewith whereby contact of said pins with the plate is prevented, an no insulating plate spaced from said block, a plurality of spring contacts mounted on said insulating plate and extending transversely of said pins one in alignment with each of said holes and adapted on the withdrawal of said pins to engage said metal plate, and electric leads connected to said spring contacts.

3. In an electric heating device, the combination of a thermostatic switchvunit detachably mounted and having contact fingers extending therefrom, spring contacts adapted to be connected with heater control circuits and engaged and depressed by the contact fingers of said thermostatic switch unit, and contact means disposed in a plane clear of intersection by said spring contacts forming a connection between said spring contacts when the latter are not depressed upon removal of said thermostatic switch unit, said spring contacts being positioned for displacement away from the plane of disposition of said contact means. I

4. In an electric heating device, the combina-- tion of a switch having switch elements adapted to open and close automatically, a plurality of contact pins electrically connected with the automatic switch elements, an insulating block through which said pins extend, an electrical conductor mounted on the rear of said insulating block and notched to clear said pins, and a plurality of spring contacts supported by said insulatlng block and having a displaceable portion disposed rearwardly of said electrical conductor and extending transversely across the path of said pins to be engaged and depressed rearwardly from said electrical conductor by contact with the inner end extremities of the pins, said spring contacts being normally held in tension by said pins and adapted on the withdrawal of said pins to move forwardly to engage said conductor;

5. In an electric heating device, the combination of a switch having switch elements adapted to open and close automatically, a plurality of contact pins electrically connected with the automatic switch elements, an insulating block through which said pins extend, an electrical conductor mounted 'on the rear of said insulating block and notched to clear said pins, an insulating plate secured to said block and forming the rear wall thereof, a plurality of terminal screws penetrating said insulating plate, and a plurality of contact strips of spring metal secured at one end under the heads of said screws and turned laterally to intersect the axes of said screws and of said pins on the inward side of said insulating plate, said strips of spring metal being normally engaged and held clear of contact with said elec trical conductor by engagement with the inner ends of said contact pins and adapted on the withdrawal of said pins to spring forwardly into electricalcontact with said conductor.

LAWRENCE IRELAND. 

